begin messageport, transferable objects, impl

Accept transfer argument for StructuredCloneData::write

Allow structured clone reads to return a boolean

Add Transferable trait

Add basic skeletons to MessagePort

Implement transfer and transfer-receiving steps on MessagePort

Use transfer and transfer_receive in StructuredClone callbacks

Implement MessageChannel

Freeze the array object for the MessageEvent ports attribute

Implement transfer argument on window.postMessage

Use ReentrantMutex instead for MessagePortInternal

Accept origin as a parameter in dispatch_jsval

Fix BorrowMut crash with pending_port_message

Detach port on closure and check for detached during transfer

Enable webmessaging tests

fix webidl

fix

components/script_traits/script_msg.rs

@@ -284,7 +284,12 @@ pub struct ScopeThings {
 
 /// Message that gets passed to service worker scope on postMessage
 #[derive(Clone, Debug, Deserialize, Serialize)]
-pub struct DOMMessage(pub Vec<u8>);
+pub struct DOMMessage {
+    /// The origin of the message
+    pub origin: String,
+    /// The payload of the message
+    pub data: Vec<u8>,
+}
 
 /// Channels to allow service worker manager to communicate with constellation and resource thread
 pub struct SWManagerSenders {